Double emission fluorescence probes based on unconventional fluorescent molecules and fluorescein isothiocyanate for ClO- and Cu2+ detection

In recent years, unconventional fluorescent molecules without conjugated rings have attracted widespread interest due to their excellent fluorescence properties, simple preparation process, good water solubility and excellent biocompatibility. Dual emission fluorescent probes are usually more accurate and sensitive, for eliminating the influence of environmental factors. This work provides a novel strategy to construct double emission fluorescent probes based on unconventional fluorescent molecules and fluorescein isothiocyanate. The aqueous solution of resulting double emission polymer dots (f-PDs) shows two fluorescence emission peaks centered at 440 nm and 510 nm under excitation at 363 nm. According to change of these two peaks after adding ions, Cu2+ and ClO- are judged quantitatively. Cu2+ or ClO- are also quench fluorescence of f-PDs linearly, as Cu2+ combines with polyethyleneimine parts of f-PDs to form complexes, while ClO- oxidize hydroxyl groups on the surface of f-PDs. The detection limits of Cu2+ and ClO-, in an aqueous solution are 6.7 nM and 14.0 nM, respectively.

Automated summary

Unconventional fluorescent molecules without conjugated rings have gained significant attention in recent years due to their excellent fluorescence properties, simple preparation process, good water solubility, and excellent biocompatibility. This study presents a new strategy to construct dual emission fluorescent probes using unconventional fluorescent molecules and fluorescein isothiocyanate. The resulting polymer dots exhibit two fluorescence emission peaks under excitation, allowing for the quantitative detection of Cu2+ and ClO-. The method demonstrates high detection sensitivity and linear fluorescence quenching.